Boosting for High Load HCCI

Olsson, Jan-Ola; Tunestål, Per; Johansson, Bengt

doi:10.4271/2004-01-0940

Cited by 111 publications

(41 citation statements)

References 17 publications

(17 reference statements)

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“…By boosting the engine in HCCI mode to extend the possible load range [12,13,14,15,16], the intake temperature will be elevated and can therefore be cooled down to a suitable level with an intercooler. The boost pressure can be controlled directly by the intake valve timing [16] which gives large freedom to operate the engine with optimum efficiency, emissions, combustion noise, cyclic variations and control strategies.…”

mentioning

confidence: 99%

The Effect of Intake Temperature in a Turbocharged Multi Cylinder Engine operating in HCCI mode

Johansson¹,

Johansson²,

Tunestål³

et al. 2009

SAE Int. J. Engines

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The operating range in HCCI mode is limited by the excessive pressure rise rate and therefore high combustion induced noise. The HCCI range can be extended with turbocharging which enables increased dilution of the charge and thus a reduction of combustion noise. When the engine is turbocharged the intake charge will have a high temperature at increased boost pressure and can then be regulated in a cooling circuit. Limitations and benefits are examed at 2250 rpm and 400 kPa indicated mean effective pressure. It is shown that combustion stability, combustion noise and engine efficiency have to be balanced since they have optimums at different intake temperatures and combustion timings. The span for combustion timings with high combustion stability is narrower at some intake temperatures and the usage of external EGR can improve the combustion stability. It is found that the standard deviation of combustion timing is a useful tool for evaluating cycle to cycle variations. One of the benefits with HCCI is the low pumping losses, but when load and boost pressure is increased there is an increase in pumping losses when using negative valve overlap. The pumping losses can then be circumvented to some extent with a low intake temperature or EGR, leading to more beneficial valve timings at high load.

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mentioning

confidence: 99%

The Effect of Intake Temperature in a Turbocharged Multi Cylinder Engine operating in HCCI mode

Johansson¹,

Johansson²,

Tunestål³

et al. 2009

SAE Int. J. Engines

Self Cite

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“…From Table 6 it can be observed that lower boost pressures and higher swirl ratios are favorable in mitigating the peak pressures. The peak pressures increase with increase in boost pressures irrespective of the swirl ratio, but the percentage increase in peak pressures is less at higher swirl ratios [33,34]. As swirl ratio increases; lower peak pressures are obtained at any boost pressure, but the percentage decrease in peak pressures is high at higher boost pressures.…”

Section: Boost Pressure (Bp)mentioning

confidence: 85%

Effective reduction of in-cylinder peak pressures in Homogeneous Charge Compression Ignition Engine – A computational study

Sharma

Rao

Murthy

2015

Alexandria Engineering Journal

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HCCI mode of combustion is known for simultaneous reduction of NOx and PM emissions besides yielding low specific fuel consumption. The nature of volumetric combustion of HCCI engine leads to the development of high peak pressures inside the combustion chamber. This high peak pressures may damage the engine, limiting the HCCI engine life period and thus demands sturdy designs. In this study an attempt is made to analyze computationally the effect of induction swirl in reducing the peak pressures of a HCCI engine under various operating parameters. For the study, specifications of a single cylinder 1.6 L, reentrant piston bowl diesel engine are chosen. For the computational analysis ECFM-3Z model of STARCD is considered. This model is suitable to analyze the combustion processes in SI and CI engines. As HCCI engine is a hybrid version of SI and CI engines, ECFM-3Z model with necessary modifications is used to analyze the peak pressures inside the combustion chamber. The ECFM-3Z model for HCCI mode of combustion is validated with the existing literature to make sure that the results obtaining are accurate. Numerical experiments are performed to study the effect of compression ratio, equivalence ratio, exhaust gas recirculation and boost pressure under different swirl ratios in reducing the in-cylinder peak pressures. The results showed that swirl ratio has a considerable impact in limiting the peak pressures of HCCI engine. The analysis resulted in achieving about 21% reduction in peak pressures are achieved when a swirl ratio of 4 with 30% EGR is adopted when compared to a swirl ratio of 1 with 0% EGR. The study revealed that out of the four operating parameters selected, lower compression ratios, higher EGR concentrations, lower equivalence ratios, lower boost pressures and higher swirl ratios are favorable in reducing the peak pressures. ª 2015 Faculty of Engineering, Alexandria University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

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“…Olsson et al [64] conducted experiments on a modified six-cylinder Scania D12 turbo charged diesel engine. The investigation studied the potential of high load HCCI through boost was evaluated and discussed, through simulations and in some cases supported by experiments.…”

Section: Effect Of Super Chargingmentioning

confidence: 99%

Homogeneous Charge Compression Ignition (HCCI) Engines: A Review

Sharma

Rao

Murthy

2015

Arch Computat Methods Eng

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The homogeneous charge compression ignition (HCCI) combustion is considered to be the principally promising future IC engine concepts. HCCI is a concept of hybrid combustion, between the Otto engine and Diesel engine. HCCI is however not a modern finding. Already in the early twentieth century hot bulb engines operated with an HCCI-like combustion. They were superior in terms of brake efficiency compared with the contemporary gasoline engines and at the same level as the diesel engines. High engine efficiencies and ultra low NO emissions and low particulates are the benefits of HCCI engines. Volumetric auto ignited combustion of the compressed lean air-fuel mixture is attributed to these benefits. There are few drawbacks also were there in HCCI engines like, low specific output, narrow operating range, lack control over the ignition process, long start up time and high emissions like CO and UHC emissions. The CO and UHC emissions can be after treated using catalytic converters. In this study a literature review on HCCI engine has been performed and the parameters affecting the HCCI combustion phasing, performance and emissions were discussed. Strategies to widen the peak load bearing capacity of HCCI engine, reducing the emissions like NOx, CO and UHC, easy autoignition were discussed in the present study.

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Boosting for High Load HCCI

Cited by 111 publications

References 17 publications

The Effect of Intake Temperature in a Turbocharged Multi Cylinder Engine operating in HCCI mode

The Effect of Intake Temperature in a Turbocharged Multi Cylinder Engine operating in HCCI mode

Effective reduction of in-cylinder peak pressures in Homogeneous Charge Compression Ignition Engine – A computational study

Homogeneous Charge Compression Ignition (HCCI) Engines: A Review

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